V-block type work holding devices have been employed in the machine tool industry for more than a century. They are typically employed for holding parts for machining or inspection. Typically, an elongated “V” groove configuration is machined or ground centrally in a block which has a provision for accommodating a horse shoe style clamp to secure the work piece within a V-groove. More advanced designs enable the V-block to be held on up to five sides. Nevertheless, the prior art suffers from numerous shortcomings which include low holding/clamping strength, marred work pieces, deformed fasteners/guides, a large profile interfering with associated machine tools, and a generalized lack of versatility.
One known V-fixture provides a “strap” device for securing a work piece in an inverted orientation. The strap itself is secured by screws into threaded lands on either side of the V-groove. The relative inaccessibility of the work piece in this type of jig limits the cutting tool to cross-drilling applications. Another V-fixture features a V-block having a tangent contact drill guide being vertically adjustable by legs straddling either side of the V-block. Screws on either side of the V-block secure the position. This prevents turning the V-block on its side for additional operations. Additionally, the straps cannot exert any significant clamping force on the work piece by the nature of its design.
Another V-block configuration employs threaded holes on the lands on either side of the V-block to secure and position a V-shaped work holding clamp. The threads do not extend through the V-block and limit work holding to the V-shaped cavity. Additionally, the clamp has a high profile which may interfere with machining operations. Furthermore, small diameter work pieces are located at the bottom of the V-shaped cavity, making it even less accessible to a cutting tool. Also, the mechanism will not permit the V-block to be held on the clamping side.
A similar device features a block having a single central V-shaped cavity and a flat base with threaded holes in lands adjacent to the V-shaped cavity. The ends of an “I” shaped tangent plate are secured to the V-block. A liner is disposed within the V-shaped cavity. This design lacks guide pins secured in the tangent clamp plate or a counter bore feature to recess the securing screws permitting turning of the fixture on any side. Additionally, the threaded holes are not threaded completely through the V-block, which limits the tool to holding the work within the V-shaped cavity.
Yet another device includes a universal angle self-adjusting V-block work piece holder including a rectangular base supporting two separate upright inverted W's that run parallel to each other along the longer sides of the rectangular base. A channel of constant width runs laterally between the two opposing vertically positioned W's. Four holes located at the apex of each peak are used as insertion points for two hexagonal screws with smooth cylindrical shafts. These shafts provide a sufficient axle for rotation of the pivoting panels to which they are attached from a through aperture extending from a ridge at the bottom of each panel. The extending portions of the separated pivotal panels are thin enough to slip between the lateral channel, and swivel when attached between the two vertical walls by the cylinder shafts. Each panel is therefore allowed movement independent of the other. Thus, the holder supports a work piece at a variety of predetermined angular orientations during the machining process.